PURPOSE: To automate the washing of a plurality of covers and to eliminate conventional complicated manual work while enhancing the efficiency of washing work.

CONSTITUTION: The opening part 4 for taking in and out a cover 3 of an article to be washed is provided to a washing box 2 and an openable and closable door 5 is attached to the opening part 4 and the support rack 6 for holding a plurality of covers 3 is arranged in the washing box 2 and a plurality of nozzles 8 for ejecting a washing soln. 7 toward the covers 3 held by the support rack 6 are provided in the washing box 2. Therefore, the moving means relatively and reciprocally moving the support rack 6 and the nozzles 8 is attached to the washing box 2 and the sequence control unit for operating the control means of the drive source of the moving means and the washing soln. of the nozzles 8 is provided to the washing box 2 and the drain valve 11 of the washing soln. 7 is attached to the bottom part of the washing box 2.