A hybrid construction machine according to the present disclosure comprises an engine, a generator connected with the engine, a converter connected with the generator, and an ESS connected with the converter. The hybrid construction machine further comprises a converter current detector which is placed between the converter and the generator or between the converter and the ESS and detects the current flowing between the converter and the generator; and an ESS current detector which is placed between the converter and the ESS and detects the current flowing between the converter and the ESS, and still further comprises: a processing unit for receiving current values detected from the converter current detector and the ESS current detector to calculate the operational time of each part; and a display unit for displaying the operational time of each part. The hybrid construction machine according to the present disclosure can calculate the operational time of each working apparatus and display the operational time to an operator, thus allowing the operator to appropriately conduct maintenance on the operational time.