The chemical liquid feeding apparatus comprises a chemical liquid reservoir, a pusher member, a pusher actuating portion, a driving section, a rotation detecting section, and a control section. The rotation detecting section detects the rotation of the driving section. The control section detects a load applied to the driving section on the basis of the rotation signal of the driving section detected by the rotation detecting section, and changes the torque produced by the driving section.薬液投与装置は、薬液が充填された薬液貯蔵部と、押し子部材と、押し子操作部と、駆動部と、回転検出部と、制御部と、を備えている。回転検出部は、駆動部の回転を検出する。制御部は、回転検出部が検出した駆動部の回転信号に基づいて駆動部に加わる負荷を検知し、駆動部により生じるトルクを変化させる。
