To discriminate whether use of an information terminal which is officially and privately utilized by an employee is business use or private use to allow official/private separation metering of terminal use time out of duty hours.

An official/private separation metering support system 1 includes: a character string comparison part 11; a conversion history DB 12; a business use determination part 13; a business word DB 15; and a duty hour DB 16, and holds character strings (business word group) to be frequently converted in a business in the business word DB 15. In use of a private-cum-official information terminal 18 out of duty hours, the character string comparison part 11 compares conversion character strings converted into Kana-Kanji by an employee with the business word group held in the business word DB 15, and holds a comparison result in the conversion history DB 12. The business use determination part 13 discriminates whether the use of the private-com-official information terminal 18 is the business use or the private use on the basis of the comparison result, and updates a duty state of the employee held in the duty hour DB 16.