Three weeks after winning Massachusetts' special U.S. Senate election, Edward Markey is set to take the oath of office.

Vice President Joe Biden on Tuesday will swear in the longtime U.S. House member as Massachusetts' junior senator. The ceremony will be in the Senate chambers and Gov. Deval Patrick plans to attend.

Markey, a Democrat, will fill the office left vacant by the resignation of John Kerry to become secretary of state.

A member of the House since 1976, Markey defeated Republican Gabriel Gomez in the June 25 special election. He will face re-election next year to a full six-year term.

Markey's swearing-in also marks the end of the tenure of interim Sen. William "Mo" Cowan, who was appointed by Patrick to fill Kerry's seat temporarily.

[Associated Press]