The 21-year-old, who is competing in his final Formula Three race at Macau this weekend, will join up with the team for next month's test at Jerez to begin his duties.

Kobayashi has been part of the Toyota Young Drivers Programme (TDP) since 2001, and for the past two years he has raced in the F3 Euro Series.

"This is a great challenge for me and I am very excited about becoming a Formula One driver," he said. "This is a fantastic opportunity for me.

"My first tests for the team last winter went well but I still have things to learn about F1 and it will be great experience for me to test more regularly for the team.

"I am sure I will learn a lot about Formula One cars and hopefully this will help me in my future career, but for now I am focused on helping the team move forward."

Kobayashi is expected to combine his role with a GP2 campaign, where his fellow TDP members Kazuki Nakajima (who will race for Williams in 2008) and Kohei Hirate raced this year.

Toyota Racing chairman and team principal Tadashi Yamashima added: "Kamui tested the car last winter and showed he had the potential to drive in F1 in the future.

"Now, after another season gaining experience in Formula Three, we believe he is ready for the challenge of Formula One.

"It is also very gratifying to see the TDP scheme delivering results and helping a promising young driver to reach F1."

Kobayashi finished fourth in this year's F3 Euro Series, scoring one win for ASM, who won the drivers' title with Romain Grosjean.