1. A machine learning apparatus comprising: a memory that stores input/output information containing information on input and information on output used for machine learning and time-point information indicating a time point of the input/output information; a processor coupled to the memory and programmed to: specify an analysis object set containing a unit-period input-output set, wherein: the unit-period input-output set includes the input/output information corresponding to the time-point information that indicates a first time point in one unit period among a plurality of unit periods, and the plurality of unit periods being obtained by equally dividing a predetermined period, and an amount of input/output information in the unit-period input-output set which varies based on a period between the first time point and a second time point; and perform machine learning by using the input/output information contained in the specified analysis object set.