A control method for an air compressor including a compressor body for compressing air and an item to be replaced used during the operation of the compressor body. The method includes computing a service time of the item to be replaced, being based upon an operating time of the compressor body, discriminating whether the item to be replaced is a manufacturer's recommended item or not, determining whether or not the service time of the item to be replaced discriminated as the manufacturer's recommend item is not longer than a first reference time, but determining whether or not the service time of the item to be replaced discriminated as one which is not the manufacturer's recommended item is not longer than a preset second reference time which is shorter than the first reference time, and issuing an alarm when determining that the reference time is exceeded.