Placement table, testing device, and testing method

There is provided a placement table having an upper surface on which a device to be processed is placed. The placement table comprises: a top plate having a placement surface for the device; a heating unit configured to heat the top plate; a plurality of temperature sensors configured to acquire temperature of the top plate at desired measurement positions in a plan view; and a positioning unit electrically connected to the temperature sensors and configured to position the temperature sensors at the measurement positions in a plan view. The positioning unit is formed of a flexible substrate having flexibility.