PURPOSE: To attain the combination of many product terms in a narrow chip area by connecting a switch between the output terminal of an AND plane and the input terminal of an OR plane, connecting the output of a control device to the control input of a switch and inputting a control signal.

CONSTITUTION: In a PLA composed of an AND plane 1 and an OR plane 2, plural outputs of the AND plane 1 are respectively connected to the input of plural switches 4, the output of plural switches 4 is connected to plural inputs of the OR plane 2 and the control input terminal of plural switches 4 is connected to a switching control device 3 of the switches 4. The control device 3 is composed of a selector to execute the switching control of a left side part AND plane 1a and a right side part AND plane 1b of the AND plane 1 with the switches 4. Thus, once after the logic is written into the AND plane and the OR plane, the combination of many product terms can be realized by a small area.