PURPOSE : To increase the input speed of the data input system of an entry device for real estate registration by facilitating its operation by selecting retrieval keys from input data and by automatically retrieving corresponding modified entry items out of an entry item memory part. CONSTITUTION : Data shown in figure A are inputted from input part 2. Next, data [purpose of registration : display of the 2nd registered person] and the following data are inputted. After the data are inputted completely, the input data are stored in entry item memory part 4 by control part 1 while [the 2nd addition number the 1st] of the order number is made to correspond to a retrieval key. Then, the input data read an input data string, one character by one character, from the initial character successively by control part 1 and whether each character code is an item identification code or not is checked. Then, when it corresponds, whether characters in the following string correspond to [purpose of registration] is checked. Thus, when it is necessary to change entry items by the input data, the entry item to be changed is automatically retrieved. Consequently, the operation is facilitated and the input speed can be increased.