Abstract: An instruction decode section judges execution/non-execution according to a state of a contact point of the last sequence program stored in a conductive/non-conductive information storage section under an execution condition of an instruction decoded by the instruction decode section. After a data memory control section reads arithmetic data are read from a data memory or a sequence program memory when the execution condition is established and an arithmetic section executes arithmetic, the data memory control section provides control so as to write the arithmetic result into the data memory. When the execution condition is not established, the data memory control section provides control so as not to read/write the arithmetic data between the data memory and the arithmetic section. When the execution condition is not established, the data memory control section does not execute arithmetic so as to proceed to next instruction.