The aerodynamic characteristics of a 5% flat plate and NACA0012-34 airfoil in low Reynolds number (Re=0.43×104∼4.1×10 4) and high subsonic flow (M=0.1∼0.6) were investigated in the Mars Wind Tunnel (MWT) at Tohoku University. A two-component balance system and Pressure-Sensitive Paint (PSP) technique have been developed to measure the lift and drag forces and pressure profiles on the model. For the flat plate, Mach number effect does not have much effect on its aerodynamic performance while Reynolds number affects the lift slope and the drag characteristics. On the contrary, for NACA0012-34 airfoil, both Reynolds and Mach number effects become more prominent. The lift curves are highly nonlinear and the drag polars are affected by behaviors of a laminar separation bubble in trans-critical condition. A comparison of the results obtained at different Mach numbers has suggested that the compressibility has an effect to stabilize separated shear layer. It has been verified by this experiment that the MWT can offer a unique capability to investigate airfoil performance in low Reynolds number and high Mach number flow.