PURPOSE: To upgrade display accuracy of residual operation time of a washing machine as a whole by detecting a city water pressure to achieve higher accuracy of estimating water supply time.

CONSTITUTION: A water pressure detection means 2 is provided to detect a pressure of water to be supplied to a water supply valve 1 and outputs of an input means 9 to be operated by a user and a water level detection means 10 for detecting the level of supply water of a washing tank are inputted into a control means 11 to control actions of the water supply valve 1, a motor 12 and the like. The control means 11 estimates water supply time upto a prescribed amount of water based on an output of the water pressure detection means 2 and residual operation time is displayed on a display means 13.