To provide an activity cost calculation system which comparably provides an activity cost regarding a job activity and can grasp efficient job improvement.

This system is an activity cost calculation system which calculates an activity cost regarding a job activity and is equipped with a data base 201 which rewritably records plural records for every job activity unit (an activity) composed of each field of a resource unit price (a resource rate) for indicating a time rate per activity, a resource consumption (a resource driver) for indicating a time needed for an activity and the number of activities (an activity driver) per unit period. Then, a computer updatably stores the resource unit price, the resource consumption and the number of activities in the data base 201 multiplies the resource unit price by the resource consumption and by the number of activities and calculates the activity cost per job activity unit.