PURPOSE: To provide the float device for pilot valve to easily prevent a pilot valve from being operated when checking overflow.

CONSTITUTION: An elbow part 30 is installed at one part of a float support arm 17 for supporting a float 15 so that the arm can be bent at this elbow part 30. Therefore, since the float 15 is freely moved up and down with this elbow part 30 as a supporting point when checking overflow, the state of preventing the pilot valve from being operated can be easily provided. When no check is performed, a traction rope 34 is unfastened and a sleeve 31 is covered with the elbow part 30 so as to prevent bending. Thus, this device can be operated similarly to the normal pilot valve.