A device for measuring three dimensional shape is configured to perform one of a first imaging operation as imaging processing of a single operation among a multiplicity of imaging operations performed by irradiation of a first light pattern of multiply varied phases, and a second imaging operation as imaging processing of a single operation among a multiplicity of imaging operations performed by irradiation of a second light pattern of multiply varied phases. The device is configured to, simultaneous with completion of the first or second imaging operation, start shifting or switching operation of said first grating or a second grating relating to said first imaging operation. The device is configured to, without waiting for completion of the shifting or switching operation, perform the other imaging operation from among the first and second imaging operations.