Gaizka Garitano's men were only promoted from Segunda Division last season, but Monday's crushing win sees them move into ninth - above Basque rivals Athletic Bilbao, who finished fourth last term.
Almeria had it all to do after just three minutes at Ipurua, as Federico Piovaccari seized on hesitant defending before finishing across goal.
Saul Berjon added Eibar's second in the 21st minute, beating Ruben via a deflection and their third arrived shortly after, Raul Albentosa heading past the unconvincing goalkeeper.
Soriano pulled one back just before the break, but the three-goal lead was restored again in the 57th minute, as Raul Navas exploited more questionable goalkeeping to head in Manu Del Moral's corner.
Their fifth arrived with 16 minutes to go as Ander Capa sent an emphatic 18-yard strike into the top-left corner, and although Edgar Mendez swiftly netted a consolation for Almeria, Eibar cruised to a resounding win.
In the day's late kick-off, a 71st-minute equaliser from Rafael Martins rescued a point for Levante in a 1-1 draw at home to Getafe.
Neither side has impressed in recent weeks, with the two teams accumulating just one win between them in their past eight league fixtures.
And it came as little surprise that the two sides could not be separated, despite Karim Yoda forcing the visitors ahead early in the second half.
Martins salvaged a point for Levante with 19 minutes to go, leaving both sides entrenched in the bottom half - Levante just three points above last-placed Elche.
