To provide a merchandise purchase assisting system reducing a communication cost for obtaining advertisement information such as a merchandise image and guiding a user to a retailer allowing sure purchase to the user.

A center 10 broadcasts merchandise advertisement information 14a including image data, sound data, and a merchandise code from a digital TV broadcasting part 11. A navigation device 20 outputs an image and a sound for advertising merchandise on the basis of the advertisement information 14a. On selection of the merchandise by the user via an operation switch group 26, merchandise selection information including the merchandise code is transmitted via a communication device 34. In this way, the center 10 makes access to a merchandise management device 50 so as to obtain information about a merchandise-available retail shop taking merchandise stock into consideration and transmits it as retail shop information via a communication part 12. Consequently, the navigation device 20 calculates a guiding path to the retail shop on the basis of the position data in the retail shop information so as to perform guidance.