A sensing baseball game apparatus (10) has a game machine (12) connected to a television monitor (18). A bat input device (32) is provided with an acceleration sensor. An acceleration signal is transmitted by an infrared-ray LED (34) to an infrared-ray receiving part of the game machine (12) whereby the game machine (12) determines a moving speed of the bat input device (32) to calculate a moving parameter of a ball to be batted. Accordingly, a batted ball is moved in the game scene according to the parameter.