The utility model belongs to the field of small kitchen appliances and relates to an electric steamer, in particular to a switch device for an electric steamer, which comprises a steaming box and a base for holding the steaming box. The switch device is arranged in the base and provided with a main control circuit and a timing heat-preservation control device, wherein the timing heat-preservation control device comprises a mode selecting device, a heat-preservation temperature controller and an operating temperature controller which are electrically connected with the main control circuit. The switch device for the electric steamer has the advantages of simplicity in control mode, simplicity and convenience in processing, and capability of realizing the timing function during heating or heat preservation.