Inside, the main altarpiece, an 18th-century Rococo work in gilded wood, houses a canvas of the Immaculate Conception made by the famous Sevillian painter Bartolomé Esteban Murillo.
In 2012, the Oratory of San Felipe Neri was the epicenter of the bicentennial celebrations of the 1812 Constitution. Following a major restoration, the church hosted more than 70 institutional, academic, and cultural events throughout the year. On March 19, coinciding with the feast of Saint Joseph, a solemn ceremony was held, presided over by the King and Queen of Spain, Juan Carlos and Sofía, which included a floral offering at the Monument to the Cortes of 1812 in the Plaza de España. These commemorations solidified the Oratory's position as a key cultural and educational space for remembering and disseminating the historical legacy of Spain's first Constitution.