Collected current monitoring device

The present invention provides a collected current monitoring device to monitor a plurality of collected currents in each current collectors and to reduce cost of equipment at the same time. The collected current monitoring device is disposed on a railcar having a plurality of current collectors, a plurality of main transformers, and a plurality of main conversion devices. The collected current monitoring device has a supply current sensor configured to detect currents supplying to any one the plurality of main transformers, at least one of collected current sensors between current collectors located at each communication paths connecting adjacent two current collectors and configured to detect current in the communication paths, and a processing unit configured to calculate currents respectively flowing into the current collectors based on distribution ratio of supplying to each of the plurality of main transformers determined according to the currents respectively detected by the supply current sensor and t