Japanese consumers have downloaded one million songs from Apple's iTunes digital music service since it launched on Thursday, the company has said.
Apple's Steve Jobs is confident his latest product will be a hit in Japan
Apple said the launch of the iTunes online music store, which sells songs by domestic and international artists, had been a "huge success".
Japan became the twentieth country, and the first in Asia, to offer iTunes.
It has sold more than 500 million songs worldwide, accounting for 80% of all legally downloaded music in the US.
Apple's iPod digital music player has already become a global success story, with nearly 22 million sold since its launch in 2001.
The US firm is facing tough competition in Japan from rival Sony whose own digital music players have been selling well in recent months.
Analysts believe iTunes' launch in Japan will boost sales of iPods, which already have a 35% share of the market.
In its first four days, a million songs have been downloaded in Japan, a faster take-up than any other country.
"We are extremely happy with the results," said Eddy Cue, vice-president of applications at Apple Computer.
"We think we have got a huge success."
Setting the standard?
iTunes is cheaper than many similar services in Japan, with most songs available for download for 150 yen ($1.35).
However, it is more expensive than its US counterpart - launched two years ago - where songs cost about $1.
About 15 Japanese record labels have signed up to iTunes but Sony Music Entertainment - Sony's music division - has yet to register.
The success of iTunes has helped Apple reinforce its pre-eminence in the digital music technology market.
"If they have a very successful launch in Japan, there is a very good chance that iTunes will become the de facto standard," said John Yang, equity analyst at Standard & Poor's.