The pyramid substructure access is found slightly above ground on the pyramid's north face.
A short descending corridor – lined with granite – leads into a vestibule, beyond which the route is guarded by a pink granite portcullis, either side of which the walls are lined with granite.
The descending corridor is 4.25 metres (14 ft) long with a slope of 24° 48′, and has a passage 1.27 m (4.2 ft) wide and 1.87 m (6.1 ft) high.
The corridor following – lined with limestone – begins with a slight ascent before becoming horizontal – and lined with granite – just prior to its terminus.
The ascending portion is 22.3 m (73 ft) long with a slope of 5°, whilst the horizontal section is 3.1 m (10 ft) long.

Precise reconstruction of the substructure plan has been rendered impossible as a result of the extensive damage that stone thieves wrought on the chambers.
As a result, sources differ as to whether the funerary apartment – estimated to be 12.6 m (41 ft) east-west by 3.15 m (10.3 ft) north-south – consisted of a single chamber, or twin chambers.

In the latter case, the antechamber lies directly on the vertical axis of the pyramid, whilst the burial chamber lies to its west.
The chamber(s) had a ceiling constructed from three gabled layers of limestone blocks, which dispersed the weight from the superstructure onto either side of the passageway preventing collapse.
The largest blocks were estimated by Perring to be 10.6 m (35 ft; 20.2 cu) long, 3 m (9.8 ft; 5.7 cu) wide and 4 m (13 ft; 7.6 cu) thick.
Despite their size and weight, all but two have been broken.
Inside the apartment's ruins, Perring found stone fragments – constituting the only discovered remains of the burial – which he believed belonged to the king's basalt sarcophagus.
The pyramid substructure access is found slightly above ground on the pyramid's north face. A short descending corridor – lined with granite – leads into a vestibule, beyond which the route is guarded by a pink granite portcullis, either side of which the walls are lined with granite. The descending corridor is 4.25 metres (14 ft) long with a slope of 24° 48′, and has a passage 1.27 m (4.2 ft) wide and 1.87 m (6.1 ft) high. The corridor following – lined with limestone – begins with a slight ascent before becoming horizontal – and lined with granite – just prior to its terminus. The ascending portion is 22.3 m (73 ft) long with a slope of 5°, whilst the horizontal section is 3.1 m (10 ft) long.
Precise reconstruction of the substructure plan has been rendered impossible as a result of the extensive damage that stone thieves wrought on the chambers. As a result, sources differ as to whether the funerary apartment – estimated to be 12.6 m (41 ft) east-west by 3.15 m (10.3 ft) north-south – consisted of a single chamber, or twin chambers.
In the latter case, the antechamber lies directly on the vertical axis of the pyramid, whilst the burial chamber lies to its west. The chamber(s) had a ceiling constructed from three gabled layers of limestone blocks, which dispersed the weight from the superstructure onto either side of the passageway preventing collapse. The largest blocks were estimated by Perring to be 10.6 m (35 ft; 20.2 cu) long, 3 m (9.8 ft; 5.7 cu) wide and 4 m (13 ft; 7.6 cu) thick. Despite their size and weight, all but two have been broken. Inside the apartment's ruins, Perring found stone fragments – constituting the only discovered remains of the burial – which he believed belonged to the king's basalt sarcophagus.
Pyramid of Sahure