Passive intermodulation (PIM) is a kind of interference generated in microwave components and systems, which has harmful impact on satellite and ground communication. Contact nonlinearity caused by non-ideal metallic contact is the main source of PIM. In this work, gap waveguide technology is adopted to solve the PIM problem, and the metal contact in microwave components is eliminated by contactless electromagnetic shielding, thus achieving a stable and efficient PIM suppression. The PIM performance of contactless waveguide is first experimentally studied with groove gap waveguide as an example, and a Ku band contactless waveguide low pass filter with series short-circuited stubs is successfully designed and fabricated. The measurement results shows that the contactless filter obtains excellent electromagnetic transmission performance, while its PIM level maintains near to the residual PIM level of the test system, and is not affected by surface treatment or connection torque, achieving a stable low PIM performance. This work provides a new idea and reference for low PIM design of microwave and millimeter-wave components and systems.