A faucet with a hidden ozone device has a body and an ozone device. The body has a base tube, an inlet pipe, a connecting tube, an outlet pipe, and a working unit. The connecting tube is mounted on the base tube. The outlet pipe is mounted in the body. The working unit has a dissolving portion and a filter portion. The dissolving portion is mounted in the working unit and is connected with the outlet pipe. The filter portion is connected with the dissolving portion, and has a liquid outlet downward formed on a bottom of the filter portion. The ozone device is connected with the body and has a machine and an ozone pipe. The ozone pipe is connected between the machine and the dissolving portion of the working unit, and is inserted into the base tube and the connecting tube.
