Disclosed are a toothbrush and a method of producing the same. The toothbrush of the present invention includes a pressure relief unit installed in a head part of the toothbrush. The unit has a plate shape and a predetermined size sufficient to cover bristles set in the head part. In the present invention, the head part is thin, and the bristles are set in the head part without using a wire. Furthermore, the present invention is easily adapted for mass production using inexpensive equipment. Also, the pressure relief unit serves as a reinforcing unit. Therefore, the head part is prevented from breaking during use despite having a reduced thickness.