To improve usability of a washing machine, which operates its lid closing means during the drain valve closing by measuring the open/close time of the drain valve, and informing a user that the lid is ready for opening based on the measuring time when the user attempts to open the lid.

When a drain valve 9 draining water in the outer drum of a washing machine is switched from 'open' to 'close', a control device 3 rotates a motor 94 as well as switches a switch 'close' 92 and a switch 'open' 93, and the switching status is detected by a drain valve status detector 31. At the same time, a time measuring device 32 start to operate, and when the switch 'close' 92 is switched from on to off, and the switch 'open' 93 is switched from off to on, the motor 94 stops and the open/close time of the drain valve is measured. When a user attempts to open the lid during dewatering by pushing an operation button, the motor 94 stops, a buzzer 4 informs a user that the lid is ready for opening based on the measured time, which eases the user.