The Near-Infrared Spectrometer and Photometer (NISP) on board the Euclid space mission has obtained near-infrared (NIR)  spectra of millions of objects, including hundreds of ultracool dwarfs (UCDs). Euclid observations retrieve images and slitless spectra simultaneously. This observing mode marks a new era in the discovery of new objects, such as L- and T-type dwarfs, which can be found from direct identification through the H2O and CH4absorption bands. NISP spectral resolution (R ∼ 450) is enough to classify the objects by the spectral type using known standard templates. 
Q1 provided more than 4 million NIR spectra in one visit to the Euclid Deep Fields. The large amount of spectra released in these fields allowed us:
- To confirm the UCD nature of almost half of the photometric candidates compiled by J. Y. Zhang et al. (2024).
- To discover at least 11 new late L- and T-type dwarfs by a specific spectral index search in Q1 data.
- To spectroscopically confirm 100 more candidates from a photometric selection conducted by M. Zerjal et al. (submitted)
We present a preliminary list of Euclid UCD templates built by the combination of the best spectra from all these searches. We include the first spectral analysis of confirmed UCDs from Q1 data; spectral classifications; determination of effective temperatures; H2O, CH4, and NH3 spectral indices; and measurements of the K I absorption doublet. 
This paper is a first step in the study of Euclid UCDs and will be improved with each subsequent data release.