A clothes treating apparatus having a liquid reservoir comprises a body having a drum therein, a liquid spraying means configured to spray liquid into the drum, a reservoir installation portion disposed at an inner upper portion of the body, a coupling means slidably installed in the reservoir installation portion, and a liquid reservoir detachably fixed into the coupling means and having an outlet on a side surface thereof, wherein a cut-out portion communicated with the reservoir installation portion and through which the liquid reservoir passes is formed on an upper surface of the body, and the liquid reservoir is connected to the liquid spraying means by sliding movement of the coupling means.