Provided is a microneedle unit comprising a case having a space accommodating a fluid and a fluid channel through which the fluid is discharged, a microneedle coupled to a lower portion of the case, a base cover disposed at the lower portion of the case, having a hole through which the microneedle passes, and being vertically movable, a guide pin coupled to the base cover and configured to open and close the fluid channel, and an elastic member configured to impart a restoring force such that the base cover is moved upward by an external pressure and then returns downward again. Therefore, the microneedle unit, which is provided to deliver a fluid into the skin with no pain and no scar, can control injection of the fluid using the guide pin, and repeatedly and conveniently control injection of the fluid using the elastic member.