PURPOSE: To control an operation time of a pump for a next day according to the actual state of an amount of water used at a preceding day.

CONSTITUTION: The number of ON times of a pressure switch 3 per one day is stored in a number of operation times memory means 9 through a number of operation times adding means 8. The number of ON times is compared with the reference number of times stored in a reference number of times memory means 12 at a given time. When the number of On times exceeds the reference number of times, a time adding means 13 adds a correction time to the given time of a time memory means 6. When it is below the reference number of times, a time subtracting means 14 subtracts a correction time to correct a given time and a timer means 5 is operated at a corrected given time at a next day to run a pump 1. Therefore, an operation time of a pump for a next day is controllable according to the actual state of an amount of water used at a preceding day and effective utilization of a power can take place.