A bus arbiter for a group of masters and a bus access control method. An arbitration priority control section output basic priority data for each of the masters. An arbitration priority generating section is provided for each of the masters, and combines the basic priority data for the corresponding master with request indication data indicating existence or non-existing of a bus access request from corresponding master to generate arbitration priority data. An arbitration priority comparing section compares the arbitration priority data for the masters with each other to determine the arbitration priority data which has the highest priority, and outputs a comparison resultant signal containing data for specifying the master corresponding to the arbitration priority data with the highest priority. An arbitration result notifying section outputs a bus use permission signal to the corresponding master with the highest priority in response to the comparison resultant signal.