A fluid meter for detecting a flow quantity and/or flow rate of a fluid flowing through a measuring section includes a measuring section part forming the measuring section, and a measuring device fastened to the measuring section part and projecting into the measuring section through an opening in the measuring section part, for detecting a measured value relating to the flow quantity and/or flow rate and/or emitting a measurement signal detecting the measured value. A measuring device fastening element is connected to the measuring device, and a measuring section fastening element is fastened to the measuring section part. The measuring device fastening element is plugged onto or in the measuring section fastening element. A locking element is plugged into each receiving region of the fastening elements and forms a form-locking connection with the fastening elements to fasten the measuring device on the measuring section part.