A launched ball detecting apparatus comprising: a ball detecting apparatus determining a specific infrared zone where the stopped ball exists as a ball existing zone (Sb) in plural infrared zones, the infrared zone irradiated with the infrared light, based on the intensity (Ub) of the reflected light in the respective plural infrared zones being adjacent one another; characterized in that the apparatus further comprises: a first object appearance determining part determining the front and end infrared zones being adjacent the ball existing zone (Sb) as front and end object appearance schedule zones (Sbe, Sbf) when the ball existing zone (Sb) is determined, and determining whether or not the object for launching the ball appeared in either one of the front and end object appearance schedule zones (Sbe, Sbf), based on the intensity (Ub) of the reflected light in the respective front and end object appearance schedule zones (Sbe, Sbf); a second object appearance determining part determining whether or not the object appeared in the remaining object appearance schedule zone other than the object appearance zone where the object previously appeared, based on the intensity (Ub) of the reflected light in the remaining object appearance schedule zone when the object appeared in either one of the front and end object appearance schedule zones (Sbe, Sbf); a ball disappearance determining part determining whether or not the ball in the ball existing zone (Sb) disappeared, based on the reflected light in the ball existing zone (Sb) when the object appeared in the remaining object appearance schedule zone; and a ball launch detecting part detecting that the ball was launched by the object when the ball in the ball existing zone (Sb) disappeared, and transmitting a trigger signal. a ball detecting apparatus determining a specific infrared zone where the stopped ball exists as a ball existing zone (Sb) in plural infrared zones, the infrared zone irradiated with the infrared light, based on the intensity (Ub) of the reflected light in the respective plural infrared zones being adjacent one another; a first object appearance determining part determining the front and end infrared zones being adjacent the ball existing zone (Sb) as front and end object appearance schedule zones (Sbe, Sbf) when the ball existing zone (Sb) is determined, and determining whether or not the object for launching the ball appeared in either one of the front and end object appearance schedule zones (Sbe, Sbf), based on the intensity (Ub) of the reflected light in the respective front and end object appearance schedule zones (Sbe, Sbf); a second object appearance determining part determining whether or not the object appeared in the remaining object appearance schedule zone other than the object appearance zone where the object previously appeared, based on the intensity (Ub) of the reflected light in the remaining object appearance schedule zone when the object appeared in either one of the front and end object appearance schedule zones (Sbe, Sbf); a ball disappearance determining part determining whether or not the ball in the ball existing zone (Sb) disappeared, based on the reflected light in the ball existing zone (Sb) when the object appeared in the remaining object appearance schedule zone; and a ball launch detecting part detecting that the ball was launched by the object when the ball in the ball existing zone (Sb) disappeared, and transmitting a trigger signal.