The Tokyo Stock Exchange's benchmark index topped the 40,000 mark for the first time ever on Monday.

The Nikkei 225 closed at a record high of 40,109. That's up 198 points, or half a percent, from Friday's close. The index gained more than 400 points at one stage on the back of semiconductor-related shares.

The rise came after New York's tech-heavy Nasdaq set a record level for the second straight day last week.

The Nikkei Stock Average late last month broke the previous all-time high set in December 1989 during Japan's asset-inflated bubble.

The benchmark set record highs four times before Monday on expectations of strong US equity markets and robust Japanese corporate performance, as well as the weaker yen.

Employees at a Tokyo securities firm celebrated the Nikkei index breaching the 40,000 mark just after trading opened on Monday.

Honma Hiroki of IwaiCosmo Securities said, "The 40,000 level was one of our goals. But there is an overall lack of excitement. It was driven by semiconductor shares. So I think this is just one stage."

Honma believes continuing to reach new highs will have a positive effect on the Japanese economy.