Disclosed is a process for producing a hydrogen-containing biocompatible solution by adding a hydrogen molecule to a biocompatible solution enclosed in a container (2i) having hydrogen molecule permeability. The process comprises a hydrogen contact step of bringing a hydrogen molecule into contact with the outside of the container (2i) in which the biocompatible solution has been contained without opening the container. The container having hydrogen molecule permeability is such a container that the dissolved hydrogen concentration in physiological saline becomes 1 ppb or more when the container containing the physiological saline is immersed in hydrogen-dissolved water in a volume of 20 times larger than the inner volume of the container for 5 hours, wherein the hydrogen-dissolved water can be maintained steadily at almost a saturated concentration (1.6 ppm at 20°C and 1 atm).
