A device, receives a unicast packet designating a unicast source and a unicast destination, and determines whether the received unicast packet is a Data Register message. Then, an intake air quantity is calculated in accordance with the engine speed and intake valve lift when an engine operating point is in a very low lift state. The light enhanced structures are disposed on the first surface. The metal-made orifice disc with the orifice formed by separate processing and the synthetic-resin-made valve seat body are removably assembled, wherein the orifice disc and the synthetic resin made valve seat body are fixed airtight to the valve main body by pressing the valve seat body via a metal inner disc.