1. A method for semiconductor device production process monitoring, the method comprising the steps of: during the production process of the semiconductor device, obtaining an SEM (scanning electron microscopy) image of a target pattern formed on a sample through a predetermined process; obtaining a feature amount of the obtained SEM image of the target pattern; adapting the obtained feature amount of the SEM image of the target pattern to an estimation model determined through comparison of the obtained feature amount to a database that preliminarily stores data of feature amounts of images obtained from SEM images obtained from various three-dimensional shape patterns (each of which hereinbelow will be referred to as “3D shape pattern”) and data obtained by measurement of cross-sectional shapes of the 3D shape patterns so as to have correlation therebetween; estimating a cross-sectional shape of the target pattern in accordance with the estimation model to which the feature amount is adapted; and determining whether the estimated cross-sectional shape of the target pattern satisfies a preliminarily set specification through comparison to the specification.