Peltier device is considered as a suitable instrument to produce heat transfer, and many methods which present thermal sensation have been proposed in the field of haptics. The bandwidth of thermal control may help a performance investigation of presenting thermal sensation. However, conventional research mainly conducts discrimination experiments of materials, and focuses relatively little on the characteristic analysis of the thermal system. In addition, when the device is driven, nonlinear terms of the device characteristic such as Joule heat is generated, and those make the bandwidth analysis difficult. On the other hand, the author has proposed observer-based temperature and heat inflow control system in the past, in which the nonlinear terms are compensated. This research uses the control systems and measures those frequency responses. The responses are compared with theoretical transfer functions which are derived by block diagrams of control systems. Experimental results show some correspondence with theoretical models, which are expected to be used for analysis of presenting thermal sensation in the future.