The present invention discloses a water quality measuring apparatus, which comprises a body in the shape of a flat panel being installed in a recession, and the recession is used to contain some sample water for measuring water quality and a positive/negative probe in the recession is used to transmit an electric charge signal of the sample water to a sampling unit of the body and then after a microprocessor calculates the level of water quality, a reading display unit on the body informs users about the level of water quality of the sample water. Therefore, the invention provides a portable and easy-to-use water quality measuring apparatus and allows users to measure the level of water quality anytime.