When an acquisition and reporting control unit of a measurement data processing unit in a development support device sends a sensor measurement start request to a portable information device in response to a collection operation start command from an application under development, an acquisition and reporting control unit of a measurement data processing unit in the portable information device starts measurement operations by a sensor. The measured raw data is continuously sent to the development support device. Data which match the collection condition are collected by a data collection unit. In response to a data request from the program under development, a data reporting unit reports the measurement data which satisfy a reporting condition to the application under development. As a result, when developing an application program which uses the results of measurement by the sensor, it is possible to provide a satisfactory development environment.