A change of a resource allocation scheme in a multi-pen supporting electronic apparatus can be made in a shorter period of time than in the prior art. A sensor controller 50 assigns communication resources to one or more pens 2, respectively, and detects a position of each of the one or more pens 2 on the basis of a downlink signal DS received from each of the one or more pens 2 using the assigned communication resources. When changing a resource allocation scheme, which indicates a structure of the communication resources or a method of using the communication resources, the sensor controller 50 broadcasts information indicating a new resource allocation scheme to the one or more pens 2.