A disposable toothbrush 1 includes a handle portion 2; a head portion 10 connected with the handle portion 2 and provided with a plurality of elastomeric bristles 10a at least at the central area of the front surface part; and a fabric medium 20 attached to the front surface part of the head portion 10 while exposing the upper end of the elastomeric bristles 10a, and made of a microfiber material provided with at least one kind of a rapidly releasable agent 21. In the toothbrush, the rapidly releasable agent can be stably attached to the fabric medium, and in use, the rapidly releasable agent can be easily separated from the fabric medium, so that the rapidly releasable agent separated from the fabric medium can be easily dissolved to increase the tooth brushing effects.