The plant, scheduled to start production by mid-2013, will be built in Prachinburi province, about 140 kilometers (90 miles) northeast of the capital Bangkok on a site with no major rivers nearby, Toshiba said.
The current plant, which is just north of Bangkok, suspended operations in October after being hit by the floods.
"The investment will be in the order of several billion yen (tens of millions of dollars)," a Toshiba spokesman said.
Most of the construction costs would be covered by flood insurance payouts, the company said.
The new factory will make chips that control the current and voltage in digital consumer products including smartphones and tablet computers.
The months-long floods last year took a heavy toll on Thailand's industrial heartland north of Bangkok, with many factories forced to close temporarily, including those of major firms such as Sony, Canon, and automaker Honda.