Preliminary review of ACA correlator that Japan has been developing was held at Mitaka. It was the first review for Japan, and was highly evaluated by the review committee members including foreign experts. We will prepare for other reviews of Band 4 (150 GHz band) and Band 8 (500 GHz band) to be held in three weeks based on the result of this review into consideration. The picture shows Sachiko Okumura, ACA Correlator Team Leader (in the center on the right of the front row) and others involved in the review committee including foreign review committee members.