To provide a web humidifier for a printer for uniformly supplying sufficient moisture to a dried web by an easy maintenance with a simple constitution.

The web humidifier for a printer comprises humidifying rollers 30 opposed in contact with front and rear surfaces of a web 10 wound on and transferred onto drive rollers 22, atomizers 32 for atomizing water to the rollers, and covers 34 covering the rollers 30 and the atomizers 32 except opposite contact parts of the web of the rollers. And, the rollers 30 are brought directly into opposite contact with the web 10 on the rollers 22.