"We had a sophisticated spacecraft at our disposal on which we could conduct technical testing and validate techniques, software and the functionality of systems that are going to be reused on future spacecraft," said Herschel's spacecraft operations manager, Micha Schmidt.
"This was a major bonus for us."
The satellite has now been placed in a safe, "disposal" orbit around the Sun.
"The last thruster burn came today, ensuring that all fuel is depleted," said the ESA statement.
BIG PIC: Herschel Spots a Hot Young Star-Forming Butterfly
Launched in May 2009, Herschel carried 2,300 litres of liquid helium coolant, which evaporated over time. Its expected lifetime had been 3.5 years.
At 7.5 meters (24.3 feet) high and four meters wide, Herschel had a launch mass of 3.4 tonnes.
It cost 1.1 billion euros ($1.4 billion), and was named after Sir William Herschel, the German-born British astronomer who discovered Uranus in 1781 and infrared radiation in 1800.
It carried three cameras and spectrometers and a primary mirror 3.5 meters (11.37 feet) across -- able to collect almost 20 times more light than any previous infrared space telescope.