A carbonaceous hard thin film (Diamond-like Carbon) with high hardness and high wear resistance is attracting attention as a low-friction material used in the space environment. It is currently proposed that ta-C films do not exhibit a low coefficient of friction in vacuum due to the effects of dangling bonds (DB). Therefore, we focused on hard carbon nitride film (ta-CNx film) with low dangling bonds. In this study, we clarify the friction characteristics of ta-CNx film under high vacuum. We succeeded in forming ta-CNx films with different nitrogen content and DB number density by the IBA-FAD method. The film was subjected to a rub test with silicon nitride balls in air and high vacuum. At high vacuum, the ta-CNx film with the lowest DB exhibited low friction, with a coefficient of friction of about 0.15, while the ta-CNx film with the higher DB caused delamination of the film. Therefore, it was suggested that the suppression of the DB number density significantly improves the peelability under high vacuum.