Scales like this are usually considered ordinal on a single-item level, thus resulting in analyses based on median etc. On an aggregate level they are often considered interval level, thus resulting in analyses based on arithmetic mean etc. Since you wrote "instrument" I think you are aggregating several liket scale items, so standard mean-level analyses (e.g., Pearson correlation) should be fine.

Article Analyzing Likert Data

Article Can Likert Scales be Treated as Interval Scales?—A Simulation Study

Because there have been so many questions here about how to work with Likert-scored items, I have collected a set of resources on this topic.

https://www.researchgate.net/post/How_can_one_help_people_create_simple_scales_from_Likert-scored_items

Treating a 5-point Likert scale as interval or ordinal has been a matter of debate (see Carifio & Perla, 2008; Chyung et al., 2017). Therefore, the purpose of statistical analysis and the importance of selecting particular statistical tests can come in handy for deciding whether to deem the 5-point Likert scale interval or ordinal.

Simply put, if you intend to employ descriptive statistics with the mean as a central tendency measure or to utilize a parametric inferential test (e.g., Pearson correlation or t test), you need normally distributed data which you can attain using an interval scale. Here are the full citations.

Carifio, J., & Perla, R. (2008). Resolving the 50-year debate around using and misusing Likert scales. Medical Education, 42(12), 1150–1152. https://doi.org/10.1111/j.1365-2923.2008.03172.x

Chyung, S. Y. Y., Roberts, K., Swanson, I., & Hankinson, A. (2017). Evidence-based survey design: The use of a midpoint on the Likert scale. Performance Improvement, 56(10), 15–23. https://doi.org/10.1002/pfi.21727

Good luck,