The development of new application fields of MEMS devices often implies a higher degree of complexity and the integration of several functionalities within these devices. In this context thermoelectric planar thin-film micro coolers become more and more important due to their utilization for the cooling and temperature stabilization, resp., in MEMS devices. Recently the investigations of micro Peltier coolers established two different types, an in-plane and a cross-plane setting. This paper reports on the investigation of design, manufacturing, and characterization of a membrane integrated thin-film thermoelectric cooling arrangement for an active temperature control and precise local cooling of the sensitive region of a dew-point sensor. The sensor chip has been designed and optimized for different applications, where the precise detection of the environmental humidity has a crucial importance. The sensor concept is based on the combination of a thermal sensor and a heater, which are encapsulated within a freestanding and thermal insulated membrane, as well as a Peltier cooler, which is fabricated on top of the membrane. To obtain a high performance concerning the maximum temperature decrease of the active cooled membrane a highly efficient thermoelectric materials combination of Sb and Bi0.87Sb0.13 was used for the fabrication of the in-plane Peltier element. For the first sensor setup a temperature decrease of 10.6 K was obtained under atmospheric condition at 293 K. In combination with an assembled two-stage Peltier cooler dew-point temperature measurements until 213 K (-60°C) were performed in a climatic exposure test cabinet.