PURPOSE: To provide a plural users information processor which is easy to operate for a user and can improve a secrecy.

CONSTITUTION: Graphic information of each user is previously stored as user management information in the area 106a of a magnetic disk 106. A central processing system 101 collates the graphic information and the user management information stored in the magnetic disk 106 by storing a locus of the movement of a mouse 104 in a main memory 105 when the user plots the graphic information by moving the mouse 104 and converting the locus stored in the main memory 105 into the graphic information when the button of the mouse 104 becomes off.