The European Solar Telescope (EST), with its primary mirror of 4.2 diameter, will be the largest solar telescope available in Europe. EST will offer Integral Field Spectropolarimetry (IFS) by incorporating the EST spectropolariMeter Based on slicEr-mirrors for the near-infraRed (EMBER). This instrument is a high-resolution spectropolarimeter that allows for the analysis of a 2D field of view by using a slicer mirror-based Integral Field Unit (IFU) as input to the spectrograph. The slicer mirror, which is placed at the focal plane of the telescope, allows the observation of the integral field of view by slicing the entire field. After that, an optical system reorganizes the field of view and provides the spectrograph with an output slit composed of multiple slitlets. The spectrograph has a Czerny-Turner design and will cover the solar spectrum from 1 to 1.8 μm. Additionally, EMBER will offer spectropolarimetry observations with a dual-beam configuration. In this contribution, we present the conceptual optical design of the spectrograph and the IFU as a solution that meets the scientific requirements.