A plan executing apparatus includes: an executing unit that executes a plan which is a sequence of processes; a processing state retaining unit that retains a processing state of a target object of the plan; an execution information retaining unit that retains execution information which is information relating to execution of a plan in execution; an interrupt instruction accepting unit that accepts an interrupt instruction during execution of the plan; an interrupt information identifying unit that identifies interrupt information relating to execution of an interrupting plan, on accepting the interrupt instruction for the interrupting plan; and an interrupt possibility determining unit that determines whether the interrupting plan is to be executed or not based on the processing state, the execution information of the plan in execution, and the interrupt information.