An information retrieval system includes a mobile communication terminal independently performing a retrieval service provided by a server that is placed outside a vehicle, and a vehicle device equipped to the vehicle and operating in cooperation with the mobile communication terminal to perform the retrieval service via the mobile communication terminal. The vehicle device includes a first vehicle-side input section that enables an input of an intended keyword by multiple times of user manipulation and a second vehicle-side input section that is preliminarily assigned with a frequently used keyword and enables an input of the frequently used keyword by single time of user manipulation. The mobile communication terminal includes a first terminal-side input section that enables an input of the intended keyword by multiple times of user manipulation and a second terminal-side input section enables an input of a predetermined keyword by at least two times of user manipulation.
