PURPOSE: To provide a server device which is inexpensive and reduces the fluctuation of the processing time.

CONSTITUTION: In a prescribed case, 8 tag giving part 1309 of a processing order controller 13 gives tags to requests to be stored in queues 1306, 1307, and 1308. Numbers of tagged requests stored in queues 1306, 1307, and 1308 are stored in tagged request number storage parts 1303, 1304, and 1305 respectively. The request in the head of each queue corresponding to information read out by each of read processing parts 100, 110, and 120 is stored in a leading request storage part 1310. A selection instructing part 1311 refers to one of requests stored in the leading request storage part 1310 in a prescribed order and selects one of requests stored in the leading request storage part 1310 based on the queue length and the number of tagged requests in each queue.