SAN JOSE, Calif. — Amid the affluence of Silicon Valley’s highly paid technology employees, an “invisible workforce” of low-paid support staff at the region’s tech companies has emerged, making one-fifth the wages of the digital workers, according to a report released Tuesday.

Janitors, landscapers, facilities cleaners and security guards providing support services to technology sites make about one-fifth the wages of software developers, systems software employees and network engineers, according to a study by labor group Working Partnerships USA.

“Although the support staff goes to work each day on the same campus as the engineers and coders, their wages are worlds apart,” the group’s report says.

The low-paid contract employees make an average of $13 an hour — well below the $62 an hour for software and networking employees, the report found.

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“This is a real problem,” said Russell Hancock, president of Joint Venture Silicon Valley, which tracks economic and employment issues in the San Francisco Bay Area. “The high-skill tech jobs are becoming very high skill. That is really driving the wage gap. There are bidding wars for tech employees.”

Although a slew of diversity reports for high-tech companies in Silicon Valley have revealed a digital workforce that is dominated by white and Asian males, the Working Partnerships report found that high-tech does have a racially diverse workforce on its campuses.

“The reality is that tech already employs the services of an army of Latino, black and immigrant workers: those who clean, guard, maintain, and cook on tech campuses every day, often for poverty-level wages,” according to the study.

Among computer and mathematical jobs in Santa Clara County, 88 percent offer earned sick days, and 85 percent of engineering and architecture jobs offer earned sick days, according to the report. In contrast, 41 percent of building and ground cleaning jobs offer sick pay.

For every tech job created in Santa Clara County, four other jobs are needed to support that tech employee, the study estimated.

The wage gap comes at a time when prices for homes and apartments have soared in Silicon Valley and other parts of the Bay Area.

“We are seeing rent increases throughout Silicon Valley, but we are not seeing a corresponding increase in wages,” Hancock said.