An occlusion detection device detects an occlusion of a flexible fluid path on either of upstream and downstream sides of a pump mechanism, the pump mechanism transporting a liquid through the fluid path by elastically deforming the fluid path. The occlusion detection device is provided with: an occlusion sensor that is disposed on the downstream side of the pump mechanism and detects an internal pressure of the fluid path during a liquid transporting operation of the pump mechanism and a data processing circuit that analyzes on which side of the upstream and downstream sides of the pump mechanism the occlusion of the fluid path occurs, based on a change of the internal pressure of the fluid path detected by the occlusion sensor and outputs an analysis result.
