A system for blood sugar level control comprising a blood sugar level control apparatus and an external device, wherein the blood sugar level control apparatus comprises: a blood sugar measuring device configured to measure a blood sugar level; and an insulin dispensing device configured to administer insulin to the inside of a body; an attachment mechanism provided on said insulin dispensing device and said blood sugar measuring device, configured to couple said insulin dispensing device and said blood sugar measuring device with each other in a relatively movable manner, wherein said blood sugar measuring device includes a first wireless data communication part configured to transmit data to said insulin dispensing device, said insulin dispensing device includes a second wireless data communication part configured to receive data from said first wireless data communication part and configured to perform data communication with the external device (6,7), wherein said attachment mechanism is adapted to relatively move said blood sugar measuring device to a first position in which said second wireless data communication part of said insulin dispensing device can receive data from said first wireless data communication part and to a second position without separating said insulin dispensing device and said blood sugar measuring device from each other, and wherein the wireless communication between the first wireless data communication part and the second wireless data communication part is an infrared communication; characterised in that said attachment mechanism is adapted to relatively rotate said blood sugar measuring device to the first position in which said blood sugar measuring device blocks the data communication to the external device and to the second position in which said blood sugar measuring device does not block the data communication with the external device (6, 7) by said second wireless data communication part. a blood sugar measuring device configured to measure a blood sugar level; and an insulin dispensing device configured to administer insulin to the inside of a body; an attachment mechanism provided on said insulin dispensing device and said blood sugar measuring device, configured to couple said insulin dispensing device and said blood sugar measuring device with each other in a relatively movable manner, wherein said blood sugar measuring device includes a first wireless data communication part configured to transmit data to said insulin dispensing device, said insulin dispensing device includes a second wireless data communication part configured to receive data from said first wireless data communication part and configured to perform data communication with the external device (6,7), wherein said attachment mechanism is adapted to relatively move said blood sugar measuring device to a first position in which said second wireless data communication part of said insulin dispensing device can receive data from said first wireless data communication part and to a second position without separating said insulin dispensing device and said blood sugar measuring device from each other, and wherein the wireless communication between the first wireless data communication part and the second wireless data communication part is an infrared communication; characterised in that said attachment mechanism is adapted to relatively rotate said blood sugar measuring device to the first position in which said blood sugar measuring device blocks the data communication to the external device and to the second position in which said blood sugar measuring device does not block the data communication with the external device (6, 7) by said second wireless data communication part.