An MTA train conductor was injured Saturday when a hammer-wielding man shattered a subway window in the Bronx, spraying glass in her face, police and sources said.

The unhinged attacker was “irate” that the train had been late, the sources said.

The unidentified conductor, 42, was taken to Lincoln Hospital, where she was being treated for cuts to her face, the NYPD said.

The incident unfolded at Grand Concourse and East 138th Street station in Mott Haven on the southbound No. 5 line shortly before 8:30 a.m., cops said.

The suspect, who was wearing an orange construction vest, and orange hat turned backward and carrying a backpack, ran off in an unknown direction, the NYPD said.

There are no arrests.

Last month, a teenager was arrested after he fired a Gel Blaster pellet gun at an MTA subway conductor’s face as her train entered a Brooklyn station, cops said.

In that instance, the conductor, 44, was aboard a southbound No. 5 subway at the Borough Hall Station when the 16-year-old boy, who was standing on the platform, fired the weapon around 1:30 p.m., police said.

The blasters discharge gel-filled pellets.

One of the pellets struck her in the left cheek and she was taken to NYU Hospital in stable condition.