Recruit Holdings Co., one of the world’s largest staffing firms, invested in San Jose, Calif.-based Savioke, Inc., a company that provides autonomous delivery service robots. The amount invested was not announced.

Savioke’s autonomous delivery robot “Relay” has been mainly used in hotels, where it replaces staff to carry toiletry supplies, linen, meals, etc. It has made at least 51,000 deliveries and been introduced in more than 40 companies, mainly in the US.

With this investment, Recruit plans to work with the company to expand the service.

“The autonomous delivery robot Relay has the potential to contribute not only to delivery in hotels, but also in various areas such as escorting, offices, healthcare and in logistics, to improve productivity and sales,” according to Recruit. “The excellent safety design features collision detection and obstacle avoidance, as well as automatic elevator operation, and the system can be used to deliver to multiple floors of buildings with complicated floor plans. Furthermore, since both software and hardware is manufactured in house, the overall cost is low.”

The investment was made by RSP Fund No. 6 LLC, operated by Recruit Strategic Partners Co. Ltd. The same fund in June in invested in Chicago-based ShipBob Inc., a provider of fulfillment services to small and medium enterprises.