A micro switch is mounted onto a mounting base attached to a controller of an automatic icemaker. The micro switch generates a signal for controlling the amount of water to be filled in an ice tray. The micro switch is fixed to the mounting base by the first fixing member and the second fixing member. The first fixing member is inserted through a mounting hole formed in a case of the micro switch. The second fixing member is arranged on a surface of the mounting base on an opposite side of a surface mounted with the micro switch, and is fixed to the first fixing member.