In 1877, he opened 'Hattori Clock Repair Shop' (服部時計修繕所, Hattori Tokei Shūzensho) in the Ginza area.

Following the great success of his first Japanese manufactured timepieces, he traveled to Europe to inspect and purchase machinery tools to keep up with western technology and productivity.

With great success, Hattori returned to Japan with new watchmaking equipment and several new production lines were born as a consequence.

His company later revolutionized watchmaking with the introduction of the first quartz movement, becoming one of the world's largest watch manufacturers.

His career accomplishments include founding the first watchmaking factory in Japan named "Seikosha", in 1892.