Zhang Zhenyu, a 40-year-old businessman from Shanghai, was sound asleep on Wednesday morning in a sleeping box at Xi'an Xianyang International Airport.

"I was on a business trip here and worked through the night. I'm flying to Beijing for a conference and I felt so tired, so I am pleased to have had a sleep in the box," Zhang told China Daily.

Seven travelers, including Zhang, have used the "sleep boxes" since they began operating on Tuesday, said Dong Liang, the airport official behind the service.

"We have 20 boxes all up, 10 have been put into operation and another 10 are being prepared for travelers," Dong said.

The sleep boxes are made to look like a small wooden house and contain a single bed, a TV, a desk, a reading light and wireless Internet. But there is no toilet inside.

"The floor area of the sleep box is about 3 square meters with a height of 2.7 meters," Dong said.

The airport started the service after being inspired by a similar program at the Moscow airport that has been operating since September.

"Our airport is the first to provide such services in China. Although only seven passengers have used them since they have been put into operation, I think they will prove popular," Dong said.

Use of the box costs 30 yuan ($4.70) for less than 30 minutes, 60 yuan an hour for the first two hours, and 40 yuan an hour from the third hour.

"I think the price is somewhat expensive, but it is a good place to sleep with good sound insulation and ventilation," Zhang said.

Contact the writers at malie@chinadaily.com.cn and luhongyan@chinadaily.com.cn