A device for measuring three dimensional shape includes a first irradiation unit, a first grating control unit, a second irradiation unit, a second grating control unit, an imaging unit, and an image processing unit. After performance of a first imaging operation as imaging processing of a single operation among a multiplicity of imaging operations performed by irradiation of said first light pattern of multiply varied phases, a second imaging operation is performed as imaging processing of a single operation among a multiplicity of imaging operations performed by irradiation of said second light pattern of multiply varied phases. After completion of the first imaging operation and the second imaging operation, shifting or switching operation of the first grating and the second grating is performed simultaneously.