The Monday temblor, whose epicenter was located seven kilometers (4.3 miles) from the town of Ossa de Montiel, near Albacete, about 220 kilometers (135 miles) southeast of Madrid, sent some panicked office workers into the streets.
According to Spain's National Geographic Institute, the quake struck at 5:16 pm (1616 GMT), while its depth has been given as 14 kilometers (8 miles).
There were no immediate reports of damage or injuries.
In 2011, an earthquake measuring 5.1 on the Richter scale struck the southeastern city of Lorca, killing at least nine people and wounding 100.
That quake, which struck at a depth of 10 kilometers and was Spain’s deadliest earthquake since April 19, 1956, damaged some 20,000 buildings, including many from the 16th and 17th centuries.