A wireless apparatus mountable to a vehicle includes a transmission function unit, a detector, an acquirer, and a controller. The detector detects a startup of the vehicle. The acquirer acquires start position information of the vehicle at a start timing at which the detector detects the startup of the vehicle. The controller examines whether a start position indicated by the start position information is within a designated region, and determines whether to activate the transmission function unit based on the examination result. Alternatively, the detector detects an operation end of the vehicle, and a startup subsequent to the operation end. The acquirer acquires position information of the vehicle at timings of detecting the operation end and the startup of the vehicle. The controller discriminates whether the distance between the positions indicated by the two pieces of the position information is greater than a threshold, and determines whether to activate the transmission function unit based on the discrimination result.