System for safety control, comprising: a first device, which is arranged to provide information capable of being used to determine whether a single staff member is present in a target area; a second device, which is arranged at an entrance of a designated area, and used for controlling the entry of staff into the designated area; at least one sensing device, for detecting whether an activated transmitting unit, required to be carried by a staff member entering the designated area, is present in the target area; and a control device (90, 208, 500), for causing the second device to allow a staff member located in the target area to enter the designated area, when it is determined that a single staff member is present in the target area on the basis of the information from the first device and it is determined using the at least one sensing device that the activated transmitting unit is present in the target area, wherein the first device comprises a third device and a fourth device, wherein the third device is a device which, each time it is operated, is arranged to only allow a single staff member to enter the target area, and the third device, when operated, is arranged to output a signal for indicating that it has been operated, and the fourth device is arranged to be used for acquiring data capable of indicating a number of staff present in the target area, and the fourth device is arranged to output a signal containing the data, wherein the information comprises the signal outputted by the third device and the signal outputted by the fourth device, and when the signal outputted by the third device and the signal outputted by the fourth device both show that a single staff member is present in the target area, the control device (90, 208, 500) determines that a single staff member is present in the target area. a first device, which is arranged to provide information capable of being used to determine whether a single staff member is present in a target area; a second device, which is arranged at an entrance of a designated area, and used for controlling the entry of staff into the designated area; at least one sensing device, for detecting whether an activated transmitting unit, required to be carried by a staff member entering the designated area, is present in the target area; and a control device (90, 208, 500), for causing the second device to allow a staff member located in the target area to enter the designated area, when it is determined that a single staff member is present in the target area on the basis of the information from the first device and it is determined using the at least one sensing device that the activated transmitting unit is present in the target area, wherein the first device comprises a third device and a fourth device, wherein the third device is a device which, each time it is operated, is arranged to only allow a single staff member to enter the target area, and the third device, when operated, is arranged to output a signal for indicating that it has been operated, and the fourth device is arranged to be used for acquiring data capable of indicating a number of staff present in the target area, and the fourth device is arranged to output a signal containing the data, wherein the information comprises the signal outputted by the third device and the signal outputted by the fourth device, and when the signal outputted by the third device and the signal outputted by the fourth device both show that a single staff member is present in the target area, the control device (90, 208, 500) determines that a single staff member is present in the target area.