A stress apparatus is reported which allows us to apply forces up to 300 N to solids perpendicular to the field in a superconducting magnet. This configuration is necessary to study stress dependences of transverse magneto‐transport effects and magneto‐optical properties in Faraday geometry. The usefulness of the apparatus is demonstrated by Hall effect and transverse magnetoresistance measurements in n‐InSb as well as far‐infrared cyclotron resonance experiments on n‐Ge.