PURPOSE: To facilitate the setting of duration or the time, by providing an operational value memory circuit.

CONSTITUTION: An operational value memory circuit 8 is provided and connected to coincidence circuit 9, display changing circuit 15, AND gate 5b, and one-shot circuit 17. In this constitution, when the display changing circuit 15 is changed to the display state of I2 input by operating an input device 4c, the contents in the operational value memory circuit 8 and a timer counter 11 are displayed in the respective display parts in a display device 16. Also, at every operation of the input device 4b, the contents in the operational value memory circuit 8 are inputted by constant value each into a minute digit part 11a. When the AND gate 5d is set to ON by operating a digit selection circuit 12 by manipulating an input device 4a, an input is supplied into an hour digit part 11b. And, when the AND gate 5d is turned ON by further operating the input device 4a, the operational value may be changed.